Replacing the Jianghus and sub-chasers?

crobato

Colonel
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Firstly this oversized enthusiaism towards catamarans and trimarans is bit weird...I mean are you choosing them just for the sake of good looks?

The proplem with trimarans and catamarans is that their seakeeping cababilities are considerably weaker than of normal displacement hulls. They are fast in calm seas, but when the seastate worsens these ships cannot go to the sea...too big default for a corvette size warship...


But unless there is a typhoon going, the Pacific is indeed a calm sea. Why do you think it was named the Pacific in the first place...the name meant "peace" as in to pacify.

Ancient Malayo-Polynesian people travelled via catamarans and trimarans, plus a great talent to read the stars, from the south easts coasts of China and Asia, to Indonesia, Taiwan, the Philippines, expanding further to the Ryukus, the Marianas, to Melanesia, Micronesia, northern Australia, New Zealand, New Guinea, then further to Hawaii, Tahiti and further on as far as the Galapagos, as well as into the Indian Ocean, into Sri Lanka, parts of Africa as far as Madagascar.
 
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crobato

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One more for Catamarans.

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"Catamarans make good cruising and long distance boats: The Race (around the world, in 2001) was won by the giant catamaran Club Med skippered by Grant Dalton. It went round the earth in 62 days at an average speed of eighteen knots."

Also the 022 is actually a SWATH.

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"The Small Waterplane Area Twin Hull (SWATH) is a hull form used for ships that require a ship of a certain size to handle equally well as a much larger ship, particularly in rough seas. Particularly in terms of its roll characteristics, a SWATH vessel "thinks it is a much larger ship". An added benefit is a high proportion of deck area for their displacement — in other words, large without being heavy. The SWATH form was invented by Canadian Frederick G. Creed, who presented his idea in 1938 and was later awarded a British patent for it in 1946. It was first used in the 1960s and 1970s as an evolution of catamaran design for use as oceanographic research vessels or submarine rescue ships.

Catamarans provide large, broad decks, but have much higher water resistance than monohulls of comparable size. To reduce some that resistance (the part that generates waves), as much displacement volume as possible is moved to the lower hull and the waterline cross-section is narrowed sharply, creating the distinctive pair of bulbous hulls below the waterline and the narrow struts supporting the upper hull. This design means that the ship's floatation runs under the waves, like a submarine (the smooth ride of a sub was the inspiration for the design). The result is that a fairly small ship can run very steady in rough seas. A 50-meter ship can operate at near full power in nearly any direction in waves as high as 12 meters."

Now I have a hard time seeing how SWATHs are not deep ocean worthy when I see deep ocean oceanographic vessels using them.

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tphuang

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Well I don't doubt that type730 is very capable system that can outperform GSh-30K... On other hand improved KashtanM has significantly better guidance system and response time compared to basic Kasthan. According to Russian sources KashtanM has 96% kill probability. Also you cant judge system performance based on one test...
it's not one test, they sent guys down there many times. PLA normally gets all of the technical data on a system before they purchase it. As for that 96% kill probability, I believe that's fairly accurate, but the question is in what scenario? How well does it handle when multiple missiles coming at it from different directions and profiles? Just because it has both gun and missile, that does not mean it's better than a system with only a gun or with only missiles.
As for HQ-7 I personally think that PLAN would be better developing new VL missile based on SD-10 family... French dropped Crotale missile and replaced it whit faster and more manoeuvrable VT1 missile rather then improving basic missile...
I thought I showed you a while back that the HQ-7 missile has been improved quite a bit from the previous Crotale missile already. The export version has 80% single shot hit probability. And I'm sure upgrades are continuously being made to it. Remember, there are numerous components to a missile system. including missile, motor, seeker, guidance, control and launching component. If you upgrade each components, you get pretty much a different system.
Ps. Maybe it would be good idea if PLAN would made CIWS based on type730 whit Kashtan missiles...
or just use QW series missiles. But as it stands with the fire control system, type 730 CIWS is extremely capable system.

As for 630 and China, China did not have any high class CIWS back in the days and China got the license production for it. As for Kashtan, not saying that it's not as good as 2 630, but that it's not as good as Type 730 CIWS. The 956EM deal was signed in 2002, so Kashtan was available and China could've had it on 051C and 054A for sure and maybe even 052B/C. 052B was full of stuff from sov, but they did not get Kashtan.
 

mehdi

Junior Member
For the CIWS China doesn't really need the :nono: Kashtan system cause it already has developed a similar system based on the :D :D :D Type 730 called the LD2000 Ground-Based Close-In Weapon System :nana: which can be adapted to any new warship China is currently building.:china:
 
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planeman

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One more for Catamarans.

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"Catamarans make good cruising and long distance boats: The Race (around the world, in 2001) was won by the giant catamaran Club Med skippered by Grant Dalton. It went round the earth in 62 days at an average speed of eighteen knots."

Also the 022 is actually a SWATH.

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"The Small Waterplane Area Twin Hull (SWATH) is a hull form used for ships that require a ship of a certain size to handle equally well as a much larger ship, particularly in rough seas. Particularly in terms of its roll characteristics, a SWATH vessel "thinks it is a much larger ship". An added benefit is a high proportion of deck area for their displacement — in other words, large without being heavy. The SWATH form was invented by Canadian Frederick G. Creed, who presented his idea in 1938 and was later awarded a British patent for it in 1946. It was first used in the 1960s and 1970s as an evolution of catamaran design for use as oceanographic research vessels or submarine rescue ships.

Catamarans provide large, broad decks, but have much higher water resistance than monohulls of comparable size. To reduce some that resistance (the part that generates waves), as much displacement volume as possible is moved to the lower hull and the waterline cross-section is narrowed sharply, creating the distinctive pair of bulbous hulls below the waterline and the narrow struts supporting the upper hull. This design means that the ship's floatation runs under the waves, like a submarine (the smooth ride of a sub was the inspiration for the design). The result is that a fairly small ship can run very steady in rough seas. A 50-meter ship can operate at near full power in nearly any direction in waves as high as 12 meters."

Now I have a hard time seeing how SWATHs are not deep ocean worthy when I see deep ocean oceanographic vessels using them.

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At least I no longer feel alone in saying that the Type-022 is probably very searworthy. Why do people keep ignoring that it has wave-piercing bows which would make it far better than a wave-riding monohull (or cat') of similar size. Look at the stats on wavepiercing catamaran ferries on ship technology.com:

1. Incat Cat-Link V ferry:
Cat-Link V has an overall length of 91.3m and a waterline length of 81.33m. It has an overall beam of 26m and a hull beam of 4.33m, excluding fenders. The distance between the hull centreline to vessel centreline is 10.83m. It has a deadweight of 500t.

The Cat-Link V hull design is optimised for speeds in excess of 40kn, to minimise wave creation. At the bow, the waterborne hulls are 10% immersed and contain 10% reserve buoyancy. The remaining 80 per cent reserve buoyancy is held in the forward central hull, located above the loaded smooth waterline. This provides a safe ride in all weather conditions and sea angles. Ride has also been enhanced by increasing the waterline length of the ferry and by the Maritime Dynamics Inc ride control system. This system provides an active trim tab mounted at the transom of each hull for trim and motion dampening.
This sort of technology must surely mitigate Golly's percieved old-school perceptions of cat's.
 

Gollevainen

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I'm not oldschool thinking...My experiences with catamarans comes from own experiences. I've said several times that I've travelled several times agross the gulf of finland with similar SWATH type of vessels than the type 22 (only that they are bigger) and they are not good seaboats by principle. Every time there is a storm comming these ships are staying in the port. These ships are fast and thats the main appeal of them but the seaworthyness is controversial. Also the volumes and weights required from warships limits these kind of ships usage.

To support my argumenting I only need to look the design around the wolrd. Give me a list of succesfull catamran or other non-displacement hull type of warships that are over 600 tons? Why there isen't any new corvette or frigate size vessels being build or under consideration for serial produgtion in other countries?
 

isthvan

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Powerplant
Below-waterline features and accessories
Stealthisation
Superstructure
Fitting the torpeados in (?)
Sensors


Ok power plant would consist of two diesels driving two controllable pitch propellers.
Superstructure would be combination of Project 2038.0 class and Oman Qahir class but I would use "X-form" arranged hull panels to avoid large flat surfaces (similar to MEKO A-200). Torpedoes would be fitted at midship.
Sensor suite would be Russian(ore Chinese equivalent) Positiv-MAE radar and Garpun-B radar. Sonar suite would be same that Golly mentioned. 76mm stays , and I'm using Kashtan because of its range(whit new missiles it has longer range then old Sea Sparrow).

it's not one test, they sent guys down there many times. PLA normally gets all of the technical data on a system before they purchase it. As for that 96% kill probability, I believe that's fairly accurate, but the question is in what scenario? How well does it handle when multiple missiles coming at it from different directions and profiles? Just because it has both gun and missile, that does not mean it's better than a system with only a gun or with only missiles.

I thought I showed you a while back that the HQ-7 missile has been improved quite a bit from the previous Crotale missile already. The export version has 80% single shot hit probability. And I'm sure upgrades are continuously being made to it. Remember, there are numerous components to a missile system. including missile, motor, seeker, guidance, control and launching component. If you upgrade each components, you get pretty much a different system.

or just use QW series missiles. But as it stands with the fire control system, type 730 CIWS is extremely capable system.

As for 630 and China, China did not have any high class CIWS back in the days and China got the license production for it. As for Kashtan, not saying that it's not as good as 2 630, but that it's not as good as Type 730 CIWS. The 956EM deal was signed in 2002, so Kashtan was available and China could've had it on 051C and 054A for sure and maybe even 052B/C. 052B was full of stuff from sov, but they did not get Kashtan.


Tphuang I said that mod HQ-7 is good and capable system and since we had same discussion a while back I will again try to explain my views... I think that basic missile has some short backs like speed and aerodynamic configuration and that PLAN would be better using subsystems developed for HQ-7 on new faster and more maneuverable missile like SD-10 family(like South Africans and French did when they decided to replace/modernize Crotale).

As for Kashtan vs. type730 debate I really don't doubt that type730 is very capable system and I'm even tend to believe that its guidance system could be better then Kashtans but there are limitations to what system can do when faced whit multiple missiles coming at it from different directions and profiles. For example if new missiles are used Kashtan can engage SSMs at longer range compared to HQ-7 and lets face it if you are facing few missiles there is limitations in how many missiles single CIWS can shoot... If you consider limited range of 30mm ammo and missile speed of min 700km/h there is little difference between type730 and Kashtan in this scenario...

For the CIWS China doesn't really need the :nono: Kashtan system cause it already has developed a similar system based on the :D :D :D Type 730 called the LD2000 Ground-Based Close-In Weapon System :nana: which can be adapted to any new warship China is currently building.:china:

I know about this system but if you consider range of TY-90 missiles this system uses I would rather use even older generation of Kashtan missiles...
 

Gollevainen

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Also the 022 is actually a SWATH.

Now it's not, it's normal wavepiercing catamaran. If it was a SWATH, the "catamaran" parts would be much bigger and in effect making the ships dispalcement much larger.

In otherwise crobato, your examples of polynesians sailing with small boats and modern sail boats are not actually comparable to this 1000 ton corvette competition. Those boats are what about 0.2 ton displacement? We are talking about warships which needs to carry lots weight.

Regarding topweight and stability, I'm really not sure about your argument, not because it isn't valid, but I think you're viewing the problem too much from a monohull's point of view. In terms of the heli, when the heli's in the hanger, it means the pad is lowered, so the ship's center of gravity is lowered. And as a trimaran, you have the 2nd and 3rd hulls to create a wider footprint to counter topweight. Also, I'm no ship architect but I surmise in these 3 hulls below the water line, you will have engines, fuel, and ballast tanks to contribute to the lower center of gravity as well. And I'm not trying to fit every possible weapon on the hull in one sitting like the Eilat. I've suggested ala carte as the mission dictates. But I do think going the way of modularity is beneficial because it offers maximum flexibility

The basic idea of ship building is that you need to dispose all the weight bellow the waterline. All weight above that is topweight. You ofcourse need to have stuff in the deck (superstructures, funnels, masts, weapons and stuff) so you will have some topweight despite all. The key is to minimalize the topweight as much as possiple. If I got your suggestion right, the helicopter pad is in the top deck level, where it should be at least half deck lower. Also this hangar type needs lifting devices which will bring more weight...not to mention how unbractical and tacticlly inflexible it is. The helipad needs to function as the main elevator. That means that it would land with the helicopter to the maindeck level. However, you cannot place structures to support new helipad, becouse the Helicopter it self blocks it, and it would bring more weigt. That sort of hanger is roofed with ligth srtuctures to cover the helicopter from the wheater. It cannot be used as helipad as long as the chopter is onboard....thats why no one
builds such, unless you desperatly want helicopter onboard ship that is clearly too small for it... If you really need helicopter capacity, build a bigger hull.

Shipbuilding has this unwritten rule that too much weird and new thecnology onboars will lead you to disaster...after 25% novelty, you will face difficoulties, the desing phase is delayed, budget exceeds, politicans begun to breath on your neck...
The other rule is that if you give some strick limit to ships size and then start seeking maxium ammount of possipilityes to add into it, it will end up in dissaster.

99% of historical warship failures can be rooted to these two principles.

So in the 'what if' phase, we should seek the best possiple solution, not the weirdest, futuristic looking or just exavagrate option...
 
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mehdi

Junior Member
Why would China buy the Kashtant system since it already has the Type 730 CIWS it doesnt make sense. Since the range of the missiles of the TY-90 missiles are not as good as you say, then upgraded versions will rectify this. There is no need or proof that China will buy the Kashtant system and incorporate in its latest ships.
 

swimmerXC

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Registered Member
To support my argumenting I only need to look the design around the wolrd. Give me a list of succesfull catamran or other non-displacement hull type of warships that are over 600 tons? Why there isen't any new corvette or frigate size vessels being build or under consideration for serial produgtion in other countries?

USN's Sea Shadow and Sea Fighter
Golly you should take a vacation to Guam or Hawaii sometimes...., you'll be surprised how calm it is in the Pacific even during a typical thunderstorm, the only times it isn't it's during a typhoon and most countries already have enough warnings before a typhoon hits to divert their ships away from it. Why else would the USN place their Pacific fleet at Pearl Harbor instead of near a large land mass like San Diego and even look at Guam which is tiny.. the USN base there and Andersen Air Force Base (hell there's B-2's there...) if the weather was as rough as you say it is in Finland then obviously they won't place their fleet in somewhere that has rough seas and bad weather...
 
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